Mechanical pencil



July 7, 1936. H. s. RICHER MECHANICAL PENCIL Filed May 26, 1954 LUQJMHarrg 5. Riche/7,' Q 6W wm. mm. Om. mm. m

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Patented July 7, 1936 FFE@ MECHANICAL PENCIL Harry S. Richer, Chicago,Ill., assigner, by mesne assignments, to Melrose Products Co., Inc., a

corporation of Illinois Application May 26, 1934, Serial No. 727,664

11 Claims.

The primary object of the invention is to provide a mechanical pencilhaving a minimum number of parts, each of which is designed so that itmay be made by relatively simple manufacturing operations and so thatthe mode of intertting of the various parts permits of relatively largetolerances in the manufacture of each part and provides an accurate andsatisfactory assembled structure.

Another object is to provide a pencil in which movement of the parts isresisted frictionally to just such an extent that no unwanted movementoccurs but yet the parts may be freely operated when desired.

A more detailed object is to provide in a pencil of this type a novelmeans for securing and supporting the tip of the pencil in the barrel,which permits the tip to operate satisfactorily and which has arelatively simple structure.

It is also an object to provide a novel structure for projecting oradvancing the lead, such structure lending itself to inexpensiveproduction and permitting the lead to be readily replaced. Y

Another object resides in the provision of a novel means for supportingan eraser.

Other objects and advantages will become apparent from the followingdescription taken in connection with the accompanying drawings, inwhich:

Figure 1 is a longitudinal section of a pencil embodying the features ofthe invention.

Fig. 2 is a longitudinal section of the tip structure of the pencilshown in Fig. 1.

Fig. 3 is an end view of the forward end of the pencil.

Fig. 4 is a transverse section taken on the line 4 4 of Fig. 2.

Fig. 5 is a transverse section taken on the line 5--5 of Fig. 1.

Fig. 6 is a transverse section taken on the line 6-6 of Fig. 1.

Fig. 7 is a longitudinal fragmentary section of a pencil having amodified form of tip structure.

Fig. 8 is a transverse section taken on the line 8- 8 of Fig. '7.

Fig. 9 is a longitudinal fragmentary section of a pencil having anothermodied form of tip structure.

Fig. 10A is a transverse section taken on the line l-Ill of Fig. 9. Y

Fig. l1 is a transverse section similar to Fig. 5 but showing a modifiedfo-rm of barrel.

The preferred embodiment of the invention comprises generally a barrelwithin which is located a means for advancing the lead of the (Cl.1Z0-18) pencil and operated by a rotative movement. Cooperating withsaid means is a guide member which is supported by the barrel. Tooperate the lead advancing means is a structure at one end of the barrelwhich in the preferred form constitutes a tip at the forward end of thebarrel for slidably supporting the lead. At the other end of the barrelis a sleeve for supporting an eraser, the sleeve being yieldably held inplace by the guide member.

In the following detailed description, it will be noted that the variousparts comprising the above-mentioned elements of the invention are ofsuch a nature that they may be made by a few simple manufacturingoperations and that very few parts are required. It will also becomeapparent that the various parts do not require close tolerances in theirmanufacture in order to coact properly with the other parts. 'Ihe pencilmay therefore be made at a low manufacturing cost.

As shown in the drawings, the barrel indicated at is an elongated tubepreferably hexagonal in shape and made of metal or composition. Withinthe barrel is a guide member 2| for supporting a lead advancing means.The guide member is preferably made from a thin-walled channel-like parthaving portions of its walls formed radially inward to provide aplurality of longitudinal ribs 22 (see Figs. 5 and 6) while part of theouter portion of the wall is shaped to t snugly within the barrel toprevent relative rotation therebetween. The ribs 22 together provide acentral guideway 23, while the space between the ribs and within theguide member forms a slot opening from the central guideway 23 andproviding an eccentric guideway 24, both guideways extendinglongitudinally of the pencil to cooperate with the lead advancing means.A plurality of such eccentric guideways or channels may thus beprovided, as indicated in Figs. 5 and 6, and between these channels areother compartments, each open at the top and of a size capable ofreceiving a lead to be held in reserve for use whenever needed. By theprovision of the ribs 22, the guide member is somewhat yieldable incharacter both internally and externally so that the barrel may beforced on the guide member if the latter is slightly large. Thus, theinternal dimensions of the barrel and the external dimensions of theguide member do not have to be held to close limits in order to have atight fit with one another.

The means for advancing the lead, in the pres ent instance, is of anespecially inexpensive construction. It comprises a helical member 25ro- .helical member. 'the plunger is formed laterally as at 28,to extendtatably supported by the central guideway 23. The member 25 is formedfrom a flat strip of metal coiled into a helix with the turns thereofspaced from each Vother vto provide a helical slot. In manufacturingthis member, a helixof indefinite length may be wound on an automaticcoiling machine and then cut into the p-roper lengths'.Y The lead,indicated at 26, ,may extend into the forward end of the helical memberin one position of adjustment, while in the rear end is a plunger 2lmade of a piece of wire rod or cast metal. The plunger is adapted to bemoved longitudinally, topush the lead forward, by the To this end, theYrear e-nd of through the slot between the turns of the helix and intothe eccentric guideway 24 where it is held against rotation. Thus, onrotation ofthe member 25, the plunger is moved longitudinally by thehelix. The helical member and plunger Y accordingly serve as twoco-acting screw elements which, together with the cooperating eccentricchannel, constitute the lead propelling mechanism for the pencil. Beforeassemblingv the helical member in the' guide member, the Vformer may bebowed slightly. The insertion of the helical member in the guide memberstraightens the former, but sufficient friction is produced therebetweenso that the helical member will rotate only on manual operation.

The' tip structure, which in the present instance is the'means foroperating the lead advancing means, is rotatably mounted in ataperedportion 30 of the forward end of the'barrel 20. The tip ycompriseswahollow member 3l tapered forwardly and longitudinally split at 32 fromits forward end inwardly to provide springY` fingers for slidablysupporting the lead 26. The rear portion of the tip is reduced indiameter as at 33 to enter the barrel' and to provide a shoulder 35abutting the end 'of the barrel. v

' VWhile the tip is rotatable in the barrelfit is desirable that suchrotation occur only when the tip is manually operated, so that the leadwill not be advanced exceptV when desired. To this end, a small amountof friction Vbetween the tip and the barrel is purposely provided, thefriction normally holding the tip against accidental rotation.Preferably the tapered end 3e of the barrel is provided'with means forproducing such friction, and in the presentV instance said means comeprises a ring or bushing 35 rotatably supporting theV reduced portion 33of the tip and non-removably ilxed in the tapered end of the barrel. Thering 35 may be a plain unbroken band havinga fairly snug fit on thereduced portion, but preferably it is a longitudinally split resilientring Y (member into the rear end of the 'reduced portion and thenpressing the reduced portion to slightly deform it and force a partofthe metal thereof into the helical slot as. shown at 31. YIn the preeYferred forrnof tip structure, such pressing action may be exerted at thesame time that a sleeve 38 is placed on the reduced portion 33 to holdthe ring`35 in place^on the tip. Thus, by theorie pressing operation,Vthe sleeve 38 is rigidly secured to the tip and the tip i's rigidlysecured to the helical member.`

An importantY feature of thev tip structure is that it is rotatablysupported at Y two spaced eration thereof. Y Y

points. For this purpose, the forward end of the guide member 2| iscountersunk at 4Q tofreceive the inner end of the reduced portion 33 andthe sleeve 38. Thus, the tip is rotatably sup-ported by the ring 35 andby the guide member 2lV at points spaced a substantial distance apartVso that the tip will be held in its properV position in spite of lateralpressure exerted thereon WhenY the pencil is in use. The tip may beprovided with knurled portions 39 to facilitate manual op-V To attach aneraser to the pencil, the guide memberY 2l at its rear end extendsbeyond the barrel a substantial distance to receive a sleeve M which isyieldable to some extent when in place. Because of the yielding natureof both the guide member and the sleeve Il l, the latter is removablyheld in place. The eraser, indicate-dat 42, may be clamped in the sleevelil by forming an inwardly turned rib 33 and an inwardly turned flangetd on the outer end of the sleeve.

In the modified form of tip structure shown in barrel, the taperedportion 3@ is longitudinally Y split from the forward end inwardly as at46, so that'the end of the barrel mayspring open sufficiently to permitthe rib 45t() slide over ythe Y reduced `portion 33 of the tip and thensnap into its groove. v Y f In the modified form shown in Figs.' 9 and10, a square-shouldered rib il of greater length is provided onfthe endof the barrel, andthe latter is longitudinally split as at 43 so thatthe ribv 4'! may be slipped over the reduced portion 33 of the tip andthen snapped into a groove in the tip. While 'the preferredcross-sectional form Yof the barrel is hexagonal, it may also be maderound as shown in Fig. ll or other Vshapes not shown herein. When Ysoshaped, the'guide member is correspondingly modified so that part of theouter portions of its walls are arcuate as shown at'Y 53 to nt snuglywithin the barrel. Byrforcing Vthe forward end of the guide `member intothe tapered portion of the barrel', suflicient friction may be providedto prevent'relative rotation.Y But, if

Vit be deemed advisable, the barrel maybe pro` vided with some meansto'prevent relative robarrel at one point. Y v

In the operation of the pencil, assume that the parts are assembled asshown inFigl; YTo advance the lead as it wears down, the tip is rotatedrelative tothe barrel and the helical mem-Y ber 2l rotates in thecentral guideway 273. Since the plunger 2? has a portion extendingthrough the helical slot of themember 2l and is held Y against rotationby the eccentric guideway 24, the plunger forces the lead forward.

When one piece of lead is used up, the eraser 42 and its sleeve di areremoved and the tip is f reversely rotated until the laterally formedportion 28 of the plunger passes out of the helical slot at the rearend.V TheY plunger may Vthus `be manually withdrawnv and a new'piece oflead inserted into the helical member. f The plunger` is then reinsertedand moved forwardly by rotation of the tip until the lead protrudes asuitable distance from the forward end of thetip.'V

The helical member permits the plunger to operate through a relativelylong range of movement so that pieces of lead of considerable length maybe employed.

It will be noted that the parts of the pencil may be readily formed bysimple manufacturing operations and are therefore relativelyinexpensive. The barrel 2! and guide member 2l may be formed fromtubing, while the helical member 25 and plunger 2l may both bemanufactured easily. The barrel will lt snugly on the guide memberbecause of the yieldable nature of the latter, and the helical memberand plunger do not have to be held to close limits in their dimensionsin order to assemble properly and operate satisfactorily. The tipstructure is also of simple construction and because of the yielding,resilient nature of some of the parts thereof, the parts hold togetherand operate properly in spite of any slight variations of size. Thus,the tolerances allowed in the manufacture of the various parts greatlyreduce the cost of producing them.

It will also be noted that because of the resilient nature of many ofthe parts, a friction is created between relatively movable parts, whichprevents accidental movement thereof but permits free manual operation.

I claim as my invention:

1. A pencil of the character described comprising, in combinatio-n, abarrel, a guide member enclosed by the barrel, said barrel having aportion extending beyond the guide member at one end, means foradvancing the lead comprising a rotatable helical member supported bysaid guide member, and a plunger within the helical member having oneend formed to extend between the turns of the helical member forengagement with the guide member, and means for rotating the helicalmember comprising a tip for holding the lead, said tip having a shankextending into the barrel with the shank rotatably supported at spacedpoints by the extending portion of the barrel and by the adjacent end ofthe guide member.

2. A pencil of the character described comprising, in combination, abarrel, rotatable means Y within the barrel for advancing the lead, arotatable tip mounted in one end of the barrel for slid-.ably supportingthe lead and for actuating said rotatable means, and a longitudinallysplit resilient ring interposed between the end of the barrel and thetip and having its ends laterally oiset to bear against the tip andfrictionally resist unrestricted rotation thereof.

3. A pencil of the character described comprising, in combination, meanswithin the barrel for advancing the lead including a rotatable member, arotatable but non-removable hollow tip mounted in one end of the barrelfor slidably supporting the lead and for actuating said means, said tiphaving a portion of reduced diameter positioned within the barrel andproviding a shoulder abutting the end of the barrel, the end of saidrotatable member being positioned within the reduced portion of the tip,a ring interposed between said reduced portion and the barrel, and alocking sleeve positioned on the reduced portion for holding said ringin position, said sleeve being pressed on said reduced portion to form arigid connection therewith and to force the reduced portion against saidrotatable member to provide a rigid connection therebetween.

4. A pencil of the character described comprising, in combination, atubular barrel, an elongated guide member, the guide member having aportion formed to provide a pair of longitudinally extending guidewaysopening laterally into each other, said portion extending within thebarrel and out beyond the upper end thereof, one guideway beingcentrally positioned and the other eccentrically positioned with respectto the barrel axis, a tip rotatably supported at one end of the barrel,an operating member open at its upper end and secured to the tip forrotation therewith and positioned within the central guideway, theoperating member having a helical slot constituting a guideway, aplunger positioned within the operating member and movable thereinto andtherefrom through the open upper end thereof, the vplunger having alaterally formed portion extending through the helical guideway into theeccentric longitudinal guideway whereby the plunger will be shiftedendwise upon rotation of the tip, and a closure for the upper end of thepencil applied over the guide member portion which extends beyond theupper end of the barrel.

5. A pencil of the character described comprising, in combination, atubular barrel, an elongated guide member, the guide member comprising achannel having longitudinally extending portions formed radiallyinwardly to provide a central guideway and extending within the barreland out beyond the upper end thereof, a tip rotatably mounted at one endof the barrel, an operating member open at its upper end and secured tothe tip for rotation therewith and positioned within the centralguideway, the operating member having a helical slot constituting aguideway, a plunger positioned within the operating member and movablethereinto and therefrom through the open upper end thereof, the plungerhaving a laterally formed portion extending through the helical guidewayinto the channel whereby the plunger will be shifted endwise uponrotation of the tip, and a closure for the upper end of the pencilapplied over the guide member end which extends beyond the upper end ofthe barrel.

6. In a pencil, the combination of a barrel open at its upper end, leadpropelling mechanism within the barrel comprising an elongated guidemember affixed to the barrel and extending in part out beyond the upperend thereof, the guide member with its extending part being of tubularform with its walls so shaped as to provide a central guideway inlateral communication with eccentric channels, and a closure :for theupper end of the pencil applied over and frictionally held in place bythe extending part of the guide member.

7. In a pencil, the combination of a barrel open at its upper end, leadpropelling mechanism within the barrel comprising a guide member ofuniform cross-section throughout its length axed to the barrel andextending in part out beyond the upper end thereof, and a closure forthe upper end of the pencil applied over the extending part of the guidemember.

8. In a pencil, the combination of a barrel open at its upper end, leadpropelling mechanism within the barrel comprising coacting screwelements positioned centrally within the barrel and an elongated guidemember aixed to the barrel, the guide member having its walls so formedas to provide for one of the screw elements a central guideway inlateral communication with an eccentric channel adapted to receive aportion of a second screw element and to one side of the channel alongitudinally disposed compartment Y at its upper end, lead propellingmechanisml Within the barrel including a longitudinal guide member'aiiixed Within the barrel and extending in part beyond the upper endthereof, said guide member being tubular with its Walls bent radiallyinward to provide guideways, and a closure for lthe upper end of thepencil applied over the extendingvpart of said guide member, the bending'of the Walls in the vaforesaidmanner providing a yielding structurefrictionally retaining the closure in place. l

` 10. In a pencil, the combination of a barrel open at its upper end,lead propelling mechanism within the barrei includingV a, longitudinal.guide memberA aixed within the barrel and extending in part beyond theupper end thereof, said guide n member comprising a tubular elementhaving longitudinal ribs extending radially inward fto provideguideways, and a closure, for the upper end of the pencil fitting overthe extending part of the guide member and frictionally held in place bythe yieldability of the guide member provided by the longitudinal ribstherein.V

11. In a mechanical pencil, the combination of lead propelling`mechanism including aV guideY guide member, said shape of the guidemember being radially yieldable and thereby frictionally n Y holdingsaid closure in place.

" Y HARRY S, YRICHER.

